Field of the Disclosure
The present disclosure relates generally to wireless communication systems and, more particularly, to the deployment of metrocells at hotspots in a wireless communication system.
Description of the Related Art
Wireless communication systems typically include a network of base stations that provide wireless connectivity to user equipment within corresponding geographic areas that are referred to as macrocells to indicate that the coverage area is relatively large, e.g., they have radii on length scales of 1-2 km. A macrocellular coverage area typically contains many macrocells. For example, a macrocellular coverage area associated with a city center may contain several macrocells to provide wireless connectivity throughout the city center. The user equipment are typically not uniformly distributed throughout the geographic coverage area, but tend to be clustered in hotspots. The communication sessions for user equipment in the hotspots can be offloaded from the macrocells to smaller cells (which may be referred to as metrocells with radii on length scales of 50-300 m) that overlay the macrocellular network. Offloading sessions from a macrocell to a metrocell may reduce congestion in the macrocell, particularly if the metrocell is deployed in a hotspot that has a large traffic density. Radio interference from macrocells may constrain the metrocell's footprint, which may be represented by the maximum effective radius of an approximately circular footprint. The footprint may therefore depend on the location of the metrocell relative to nearby macrocells. Only traffic from sessions within the metrocell footprint will offload from the macrocell to the metrocell.
Traffic hotspots within a macrocellular coverage area can be identified using a brute force method that evaluates the amount of traffic in a two-dimensional array of locations distributed uniformly over the macrocellular coverage area. For example, a potential metrocell may be placed at each location in the two-dimensional array and the number of hotspot sessions available for offloading to the potential metrocell may be counted. The potential metrocell locations may then be ordered based on the number of sessions within their footprints and metrocell locations that have a higher number of sessions may be chosen as the locations for actual metrocell deployments. The computation time required to implement the brute force method scales with the area of the macrocellular coverage area (e.g., the square of the radius of a circular macrocellular coverage area) and with the area of the individual hotspots (e.g., the square of the radius of the hotspots).